This application incorporates by reference, and claims priority to and the benefit of, German patent application serial number 10036100.5, which was filed on Jul. 25, 2000.
The invention generally relates to articles of footwear and soles therefor. In particular, the invention relates to a sole for athletic or sports footwear that includes openings for ventilation and vapor exchange.
The technical development of shoes, in particular sport shoes, has advanced in recent years. Presently, shoe constructions can be adapted to accommodate the mechanical stresses arising on a wearer""s foot during different kinds of sporting activities and provide a high degree of functionality and wearing comfort. In spite of these developments, it was not possible to manufacture shoes that, in addition to providing damping and support for the foot, also provide a comfortable climate for the foot. For example, the use of foamed plastic materials, which is common in modern sports shoes, prevents heat and humidity from being sufficiently transported away from the foot to efficiently avoid a hot feeling, an unpleasant odor, or a risk of diseases of the foot. These disadvantages present a severe problem in the case of sports shoes. Because of the increased physical activity during sporting activities, more heat and humidity arise in the foot area within the shoe. For this reason, there are different approaches to provide ventilation and removal of sweat from the foot area within the shoe.
For example, Swiss Patent No. 198 691 discloses an insole, wherein a leather sole provided with holes is arranged as a top layer on a frame-like supporting layer. The foot is to be surrounded by air from all sides to account purportedly for the breathing requirements of the foot sole. A similar construction is disclosed in United Kingdom Patent No. GB 2 315 010. Both Swiss Patent No. 198 691 and United Kingdom Patent No. GB 2 315 010 are hereby incorporated herein by reference. A disadvantage, however, is that no exchange takes place between the volume of air arranged below the foot sole and the surrounding air. As a result, humidity and bacteria can accumulate in the shoe.
Another approach is to connect an air volume, usually provided below the insole, with the outside air via lateral openings. The repeated compression of the shoe sole, a result of the action of the foot while running or walking, purportedly causes the warm air and humidity from the air volume inside the shoe to be pumped to the outside air with each step, thereby transporting humidity away. Examples of such shoes are disclosed in German Patent No. DE 121 957 and U.S. Pat. Nos. 5,035,068, 4,837,948, and 5,655,314, all of which are hereby incorporated herein by reference.
There are, however, problems with the foregoing concepts. First, the pumping action provided by the compression of the sole is too weak to assure a substantial exchange of air via the lateral openings, which may be several centimeters away. As such, the warm air and the humidity are only slightly moved back and forth without actually leaving the air volume from within the shoe. Second, a recess arranged below the insole, which contains the air volume, is so big that a soft shoe is created, which is mechanically unstable.
According to another concept, arrangements of partly closeable openings on a shoe upper can be used, examples of which can be found in U.S. Pat. Nos. 4,693,021, 5,357,689,and 5,551,172, all of which are hereby incorporated herein by reference. These arrangements do not have any influence on the aforementioned disadvantages, because the heat and humidity dispensed by the foot is predominantly arising in the foot sole area. As such, openings on the shoe upper do not significantly contribute to the ventilation of the foot sole area. Therefore, the arrangement of ventilation openings on the shoe upper does not result in a shoe that provides a comfortable and healthy foot climate.
Yet another approach is disclosed in U.S. Pat. No. 4,290,211, which is hereby incorporated herein by reference. Here, an outsole is perforated by a plurality of conically tapered openings and an insole has perforations that exactly coincide with the openings of the outsole. Although sufficient ventilation may be possible by this direct vertical connection from the foot sole to the outside, multiple through-holes reduce the mechanical stability of the sole, so only a few openings can be provided. This, however, reduces the desired ventilation effect. As a result, such a simple perforation of the shoe sole has not become popular, in particular in the case of sports shoes.
With the introduction of so-called xe2x80x9cclimate membranes,xe2x80x9d one example of which is the GORE-TEX(copyright) brand sold by W. L. Gore and Associates, the holes in the outsole are covered by a breathable membrane. Such constructions can be found in International Patent Application Publication No. WO97/28711 and European Patent Application No. EP 0 956 789, which are hereby incorporated herein by reference. Although the use of climate membranes may lead to improved watertightness of the shoe, the above described disadvantages concerning the stability of the shoe are not overcome, but worsened, because even with a breathable membrane, more through-holes in the sole are necessary to assure sufficient ventilation of the foot sole.
Furthermore, International Patent Application Publication No. WO99/66812, European Patent Application No. EP 0 960 579, and U.S. Pat. Nos. 5,983,524 and 5,938,525, the disclosures of which are hereby incorporated herein by reference, disclose combinations of the above-described approaches, but without overcoming the respective disadvantages. In one example, the five-layer system disclosed in U.S. Pat. No. 5,983,525 consists of an outsole, a membrane, a protecting layer, a filling layer, and an insole with isolated arranged perforations in their respective layers. This system is far too dense for effective ventilation of the sole area, even if breathing active materials are used.
The climate control shoe sole of the present invention overcomes the disadvantages of known sports shoes and methods for transporting heat and humidity from a wearer""s foot. Generally, the sole, as described herein, assures a comfortable and healthy foot by providing proper ventilation and air exchange within the shoe, while at the same time preserving the mechanical stability required for sports shoes.
In one aspect, the invention relates to a sole for an article of footwear. The sole includes an insole layer with a plurality of first openings, a support layer with a plurality of second openings, and an outsole layer with at least one third opening. A substantial portion of the plurality of first openings in the insole layer are interconnected. The openings in each of the layers are arranged such that the second openings in the support layer partially overlap the first openings in the insole layer and the at least one third opening in the outsole layer partially overlaps the second openings in the support layer.
In another aspect, the invention relates to an article of footwear including an upper and a sole. The sole includes an insole layer with a plurality of first openings, a support layer with a plurality of second openings, and an outsole layer with at least one third opening. A substantial portion of the plurality of first openings in the insole layer are interconnected. The openings in each of the layers are arranged such that the second openings in the support layer partially overlap the first openings in the insole layer and the at least one third opening in the outsole layer partially overlaps the second openings in the support layer. In one embodiment, the upper is made of a reinforced mesh material. Optionally, the article of footwear can include a climate control sock that has a two layer mesh construction.
In various embodiments of the foregoing aspects of the invention, the plurality of first openings are distributed over substantially the entire insole layer and the first openings may be generally circularly shaped. In some embodiments, a first portion of the plurality of first openings are disposed in at least one of a ball region and a heel region of the sole and a second portion of the plurality of first openings are disposed in the remaining regions of the sole. The openings of the first portion may be smaller than the openings of the second portion. In one embodiment, the openings of the first portion are less than about 3 millimeters (mm) in diameter and the openings of the second portion are greater than about 4 mm in diameter. In other embodiments, at least one channel interconnects a portion of the first openings and the channel is disposed on a bottom side of the insole layer.
In some embodiments, the support layer is a substantially compression resistant semi-rigid chassis that controls deformation properties of the sole. The support layer may extend along a heel region and/or a ball region of the sole. In various embodiments, the plurality of second openings in the support layer may be disposed in a toe region and/or an arch region and/or an upwardly extending portion of the sole. In some embodiments, the plurality of second openings form a grill pattern. In other embodiments, the support layer may further include a support element disposed in the arch region of the sole. The support element interconnects a forefoot part and a rearfoot part of the sole, and the support layer and/or the support element may sideways encompass a wearer""s foot in the arch region and/or the heel region of the sole.
In additional embodiments, the outsole layer of the invention may include a plurality of sole elements, for example a forefoot element and a rearfoot element. The outsole layer may extend along the heel region and/or the ball region of the sole. In various embodiments, the at least one third opening is disposed in the toe region and/or the arch region of sole and overlaps with corresponding second openings in the support layer. The outsole layer may also sideways encompass the wearer""s foot in the heel region and/or a forefoot region of the sole. In other embodiments, the outsole layer further includes a cushioning layer and/or a tread layer.
In still other embodiments, the sole may include a membrane disposed between the support layer and the insole layer. In some embodiments, a shoe in accordance with the invention may include a flexible net-like element for selective reinforcement of parts of an upper. The flexible net-like element may be disposed in a heel region of the upper, for example, the medial and/or lateral side of a wearer""s ankle.
These and other objects, along with advantages and features of the present invention herein disclosed, will become apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations.